Hydrogen molecules (atoms) have heretofore been known to have reducibility, and have been put in practical application for reduction reaction (hydrogenation reaction) in chemical synthesis, etc.
However, the matter as to how and by what mechanism the relatively stable hydrogen molecules could exhibit reducibility is in the process of developing studies. It has been presumed that, just before the reaction, hydrogen could be in the active state “atomic hydrogen”, or “nascent hydrogen”, however, the theoretical rationale for the physical properties is as yet still left unsolved.
For noticeably getting out the reducibility of hydrogen molecules, in general, a metal catalyst or the like has been used for the purpose of lowering the activation energy for reaction. According to the method of using such a metal catalyst, it is said that the hydrogen adsorbed by the metal surface becomes atomic hydrogen and acts for reduction. On the other hand, it is known that, when hydrogen molecules have dissolved in water, they exhibit an extremely high reduction potential, and it is understood that this phenomenon would be based on the same action as above. However, the reducibility character and the stoichiometric nature thereof are as yet left unsolved.
For example, it is known that when hydrogen molecules are dissolved in water, the oxidation-reduction potential therein changes from about 250 mV before the dissolution to about −500 mV after the dissolution. Owing to such a high reduction potential of the dissolved hydrogen water, the dissolved hydrogen water is anticipated to have the function of antioxidation and active oxygen scavengeability, and in particular, since the relation between active oxygen and human health has been reported, many researchers and persons on the street are concerned about this issue.
In fact, we face various realistic evidence that iron rusts in tap water but not in hydrogen water, and green tea does not discolor in brown in hydrogen water; unfortunately, however, we could not reach any inflexible academic verification as yet.
One factor is that active oxygen has an extremely short life. For example, some investigations have been made for capturing the behavior of active oxygen having a short life, according to a method of spectroscopy in a system where the signals are rapid, such as ESR (electron spin resonance) or luminescence measurement; however, it is said that further investigations in novel aspects would be necessary for obtaining detailed knowledge relating to the reaction between dissolved hydrogen in water and active oxygen.
The present inventors have made investigations for the technology of obtaining a reducible hydrogen solution with a large quantity of hydrogen dissolved therein within a short period of time by dispersing hydrogen microbubbles in water or in solution (see Patent Reference 1); and based on the previous knowledge, the inventors have further investigated the relation between dissolved hydrogen and active oxygen in water stoichiometrically and from the viewpoint of capturing the reaction speed in a large volume, thereby exploring a novel method for obtaining useful knowledge in application of dissolved hydrogen to active oxygen scavenging.
[Patent Reference 1] WO2008/156171